Telephone-exchange system.



A. E. LUN'DELL.

TELEPHONE EXCHANGE svsmwp Patented July 17,1917.

3 SHEETS-SHEET l lm/wvfo'r; Alba/4 [,L Mde/A APPLICATION HLED SEPT-22. 1916.

A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM.

Patented July 17, 1917.-

3 SHEETS-SHEET 2 APPLICATION FILED SEPT-22. l9l6.

A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM;

KPPLICATION FILED SEPT-22, I916- T n Patented July 1!, 1917.

.3 SHEETS-SHEET 3- EQSK -QQS o T Fit FF.

ALBEN E. LUN DELL, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

rasasea.

Specification of Letters Patent.

Patented July 1?, 191%.

Application filed September 22, 1916. Serial No. 121,562.

To all whom it may concern:

Be it known that I, ALBEN E. LUNDELL, a citizen of the United States, residing at New York, in the county of Bronx and State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and eXact description.

This invention relates to telephone exchange systems, and more particularly to improvements in automatic or semi-automatic telephone exchanges.

It is the Object of the present invention to provide a new and improved circuit arrangement for controlling the operation of automatic switching devices, which are adapted to hunt for and seize an idle set of terminals representing a telephone line, such as a trunk leading to a selector switch.

More particularly the object of this invention is to providea circuit arrangement for hunting switches which are adapted to be successively set into readiness for. operation, whereby the starting of a switch to hunt for a certain set of terminals, is definitely prevented after another switch has been started to hunt for said set of terminals.

According to the present invention, a plurality of finder switches adapted to associate a switch controlling device, such as a sender, with a trunk or link circuit assigned by an operator, is successively set in readiness for service preferably under the control of an allotter. Associated with each link or trunk circuit, is a controlling apparatus such as a sequence switch controlling the circuits of a selector by means of which the trunk circuit may be extended under the above mentioned. 09rd.find er, will start to hunt for the assigned trunk and'will thus be uselessly set into motion.

To prevent the occurrence of this, the present invention provides means, preferably in the form of a relay associated with the trunk circuit, which will prevent the starting of another cord finder under the control of the sequence switch associated with the same selector, during the time elapsing between the allotment of another cord finder and the movement of the sequence switch into said operating position. This isdone by causing the relay to open the starting circuit of the finders as soon as the next cord finder is allotted. The relay maintains the starting circuit open until the sequence switch is moved into the said operating position, in which position the sequence switch contacts controlling the starting circuit, are open.

The drawings represent a semi-automatic telephone system embodying the present invention, and should be considered by placing Figure 2 to the right of Fig. 1, and

Fig. 3 below Fig. 2.

Only so much is disclosed of a semi-automatic telephone system as is necessary for a clear understanding of the invention. A more complete disclosure of the circuits controlling the operation of the selector switches, the cord finders, the sender and the associated apparatus, may be had from Patent 1,115,389 issued on January 18, 1916 to A. E. Lundell.

The automatic selector switches shown in the drawings may be of a structure similar to that shown in Patent 1,123,696; the cordfinder switch shown in Fig. 3, however, will be provided with but a single set of brushes.

The sequence switches and the allotted switch shown in the drawings may be similar to the sequence switch structure disclosed in Patent 1,127,808; The numerals which appear adjacent to the contacts of such switches, diagrammatically represented in various portions of the drawing, indicate the positions of the respective switches, at which these contacts are closed with the exception that the controlling contacts or normal contacts, one of which appears immediately above the motor magnet of each of these switches, are open only at the positions indicated by the numerals adjacent thereto, and therefore the switches can stop in only these positions.

It will be obvious, however, to those skilled in the art, that instead of the apparatus disclosed in the mentioned patents, other apparatus may be successfully employed with- 'out departing from the spirit of the present invention. ,7 A q A full understanding of the invention may be had from the tollowing description I and the appended claims.

' The subscriber at substation 100, desiring to obtain a connection with a subscriber at station 200, removes his receiver from the switchhook, causing thus the energization of a line relay 101, which, in turn, actuates a calling line signal 102. An A -cperator whose telephone head set is shown at 103,

noticing the signal 102, inserts a plug 104 into an answering jack 105 in which the can ing subscribers line terminates. A circuit is now closed from ground, through the windinglof a cut-off relay 106, the sleeve contacts of jack 105 and plug 104, a resistanc'e 107, and a supervisory signal 108 to grounded battery. The relay 106 becomes energized, and by disconnecting the line relay 101, causes the release of signal 102.

'Lamp 108 cannot light up due to the factthat a calling supervisory relay 109, Which has been energized over the line circuit, closes a shunt around it. By depressing her listening key 110, the A operator connects hertelephone set 103 into telephonic association with the calling subscribers station 100 over a cord or link circuit 111.

Having received the called subscribers number, the A-operator depressesa call circuit button 112, and establishes .a connection over a call circuit 113 between her telephone 103 and a B-operators telephone set, shown at 201. The B-operator receives the number of th'e called subscriber from the A- operator and instructs the latter to extend the calling line to an idle trunk leading to the .B-operatorsposition. Supposing that trunk 114,115 is to be used, the A-operator inserts a plug 116 into a jack 117 in Which the trunk terminates at her board. A circuit is closed thereupon for a called super-v visory lamp 118, and the trunk is guarded in the well-known manner.

Another circuit is closed from grounded battery through the left han'd Winding of a relay 202, the primary winding of a repeating coil 203, conductor 114, the tip contacts of jack,117 and plug 116, the normal contact of a ringing key. 120, and the secondary winding of a repeating coil 121 to ground.

'Relay 202 becomes energized. o

i The B-operator. proceeds now to build up theconnection to the called subscribers station. By depressing an assignment key 204,

1 she establishes a circuit from ground through the contacts of this key, a contact 205 and magnet 306 to grounded battery.

the power magnet of a sequence switch 206 to grounded battery. Under the control of a. normal spring 207, the sequence switch is moved out of position 1 and into position 2.

As soon as sequence switch 206 reaches position 2, a starting circuit is completed for a cord finder (Fig. 3) from ground through a sequence switch contact 208, the armature and back contact of a relay 209, conductor 210, contacts 300 and 301 of a sequence switch 302 and the winding of a relay 303 to grounded battery. Relay 303 closes a circuit from ground through its right-hand armature and front contact, a contact 304 and the power magnet of sequence switch 302 to grounded battery for driving this sequence switch out of position 1 into position 2. A circuit is closed thereupon from ground through the righthand armature and front contact of relay 303, a sequence switch contact 305, and the winding of a By attracting its armature, magnet 300 presses a cord-finder brush rod 307, carrying wipers 308, 309 and 310, and commutator brushes 311 and 312 against a roller 313 constantly rotating in the direction indicated by the arrow. Wipers 308 to 310 travel over the contacts of a terminal bank 314 in which conductors individual to trunks such as 211,

212 terminate. As soon as the contacts representing trunk 211, 212, the sequence switch 206 of which is in position 2, are reached,

a circuit is completed from grounded battery through the winding of a relay 315, a sequence switch contact 316, wiper 309, terminal 317, conductor 318, and a sequence switch contact 213 to ground. Relay 315 closes a locking circuit for itself from grounded battery through its winding, a sequence-switch contact 319, the right-hand front contact and armature of relay 315, wiper 310, terminal 320, conductor 321, the winding of relay 209 and a sequence-switch contact 214 to ground. As long as sequence switches 206 and 302 are in position 2, relay 209 cannot become energized due to the existenc'e of a shunt path through sequenceswitch contacts 316 and 213 to ground.

At its left-hand armature, relay 315 opens a circuit extending from grounded battery through the winding of relay 303, sequenceswitch contacts 301 and 322, and the back contact and armature of relay 315 to ground through which relay 303 was held energized when 'sequence switch 302 left position 1}. During the upward travel of the cord finder, brush 311 was riding over a commutator plate 323, the insulated segments 324 of which are so arranged with respect to the terminal bank 314 that when brush 311 contac'ts with one of them, the Wipers 308 to 310 are exactly centered on a set of terminals.

soon, therefore, as brush 311 reaches an insulated segment 324, after the energization of relay 315, relay 303 becomes deenergized, its holding circuit, extending from ground through commutator brush 311, the conducting plate 323, conductor 325, and the left-hand armature, front contact and winding of relay 303 to grounded battery, being opened. Upon the deenergization of relay 303, a circuit is closed from ground through the right-hand armature and back contact of this relay, a contact 326 and the power magnet of-sequence switch 302 to grounded battery, and under the control of a normal spring 327, this sequence switch is moved out of position 2 into position 3. Contact 316 is now open and relay 209 becomes energized and opens at its back contact, the starting circuit for this cord finder.

The B-operator now depresses a starting key 332 for closing a driving circuit through a sequence-switch spring 333 to drive sequence switch 302 out of position 3 and into position .7.

In position 7 of sequence switch 302, a circuit is closed for actuating a cord-finder allotter 360, which is assumed to be in position 1. This circuit extends from grounded battery, through the power magnet of allotter 360, sequence-switch contact 361 and allotter contact 362 to ground, and under the control of a normal spring 363, the allotter is moved into position 2.

A. sequenceswitch 302 controls the operation of a cord finder (not shown), similar to the one represented in Fig. 3, in the same manner as sequence switch 302. Sequence switch 302 is standing now in position 18 where it has been moved in a manner to be described later in connection with sequence switch 302.

When the allotter reaches position 2, a circuit is closed from ground, through allotter contact 364, a contact 365 and the power magnet of sequence switch 302 to grounded 3 battery. Under the control of a normal spring 327, sequence switch 302 is moved out of position 18 into 1 and set in readiness for service. In view of the fact that at this time, sequence switch 206 is still in position 2, a circuit might be established from grounded battery, through the winding of relay 303,ccontacts of 301 and 300' of se quence switch 302, conductor 210, the back contact and armature of relay 209, and sequence switch contact 208 to ground; If the establishment of such circuit would be possible, relay 303' would close a driving circuit through a contact 304 of sequence switch 302 for moving this switch into position 2, whereupon the associated cord finder would be needlessly started, due to the actuation of its motor or driving magnet corresponding to magnet 306. However, as stated, the starting circuit leads through the back contact of relay 209 and as it was Set forth above, the circuits of this relay are so arranged that as soon as sequence switch 302 moves out of position 2, 2'. 6. upon the setting of wipers 308, 310 onto terminals 334, 317 and 320, and while sequence switch 206 is in position 2, relay 209 is energized. It will be seen, therefore, that the needless starting of another cord finder is positively prevented.

When sequence switch 302 reaches posi tion 7, a fundamental circuit is established from grounded battery through the winding of a relay 230, sequence switch contacts 231 and 232, a conductor 233, terminal 334, wiper 308, the windings of a stepping relay 335, the back contact and armature of the upper counting relay 0 and the sequence switch contact 336 to ground. Relay 230 closes a locking circuit for itself over its left-hand front contact and armature, and a circuit from ground, through its right-hand armature and front contact, a sequence switch contact 234, and the power magnet of sequence switch 206 to grounded battery for driving this sequence switch out of position 2 into position 3.

In position 3 of the sequence switch 206, its contacts 214 and 270 are closed causing the short-circuiting of relay 209. The deenergizationof relay 209 at this time cannot result in the starting of the allotter cord finder associated with sequence switch 302, because sequence switch 206 opens its contact 208 as soon as it is moved out of position 2. Obviously this allotter cord finder may be used to associate the sender (after the setting of the selector) with other trunks, z. e. selectors.

A circuit is closed from grounded battery through the winding of a magnet 235, sequence switch contacts 236 and 237 and the right-hand front contact and armature of relay 230 to ground. By attracting its armature, magnet 235 presses the brush rod 238, carrying wipers 239, 240 and 241, and brush 242 of a selector switch 243 against a roller 244, constantly rotating in the direction indicated by the arrow for causing the upward travel of the brush and wipers.

Let us suppose that the called subscribers number is 9876 and that the operator has depressed keys 328, 329, 330 and 331.. Upon the energization of the stepping relay 335, a circuit is established from ground through the armature and front contact of this relay, a sequence switch contact 337, a conductor 338, the contact of key 328, conductor 339, the armature and back contact of the upper counting relay 9 and the winding of the lower counting relay 9 to grounded battery. The lower counting relay 9, upon energization, establishes a locking circuit extending from ground through a sequence switch contact 340, conductor 341, the armature and front contact of the lower counting relay 9, the windings of the upper and lower court ing relays 9 to grounded battery. Due to a shunt path established through the front contact of the stepping relay 335, the upper counting relay cannot become energized.

.As soon, however, as brush 242 engages a shunted out under the control of brush 2412,

the upper counting relay 8 becomes also energized and the operation of these counting relays will continue until the wipers of selector24i3 reach the terminals oi? a trunk predetermined by the thousands key 328,

whereupon the upper counting relay 0 becomes energized and opens at its armature and back contactgthe fundamental circuit causing thus the de'einergization of relays 335 and 230, and the driving of sequence switch 302 out of position 7 into position 9.

Upon the deenergization of relay 230, a circuit is closed from ground through the right-hand armature and back contact of relay 230, a contact 247, and the power magnet of sequence switch 206 to grounded battery for driving this sequence switch out of position 3 into position 8. As soon as this se quence switch is moved out of position 3, the circuit of magnet 235 is interrupted, and assuming that the first trunk in the designated group is idle, the selector wipers will be arrested in their movement.

Key 239 controls the setting of a selector switch 24 and keys 330, 331 the setting of a connector switch 2419.

The control of these switches is accomplished in substantially the same manner as'described in connection with selector switch 2 13. After the sending of the hundreds series of impulses, sequence switch 302 moves into position 11 and sequence switch 206 moves into position 10. Again, after the sending of the tens series of impulses,sequence switch 302 moves into position 13. Lastly, after the sending ofthe units series of impulses, sequence switch 302 moves into position 17 and sequence switch 206 moves into position 16. When sequence switch 302 passes through and out ofposition 16, relay 315 becomes 'deenergized .due to the opening of its circuit at contact 319.

' 1A circuit is thereupon established from brush rod 307 against a roller 352, constantly rotating in the direction indicated by the arrow, and the cord finder will thus be restored to normal position. As soon as brush 312 reaches a plate 353, a circuit is established from ground through brush 312, plate 353, a contact 354: and the power magnet of sequence switch 302 to grounded battery for moving this sequence switch out of position 17 into position 18.

Sequence switch 302 remains in position 18 until the allotter again returns to position 1 and closes a circuit from ground, through its contact 362, a contact 365 and the power magnet of sequence switch 302 to grounded battery, whereupon this switch is moved into position 1.

When the called subscriber at station 200 removes his receiver from the switchhook, a supervisory relay 250 becomes energized and closes a circuit including the right-hand winding of relay 202 and the winding of a called supervisory relay 119 in series. The supervisory relay 119 shunts out lamp 118. Under the control of key 120, relay 202 may be controlled to cause the re-ringing of the called station in case of premature disconnection on the part of the called subscriber. The re-ringing of the called station may be controlled in a manner disclosed in Patent 1,183,890 issued May 23, 1916, to A. E. Lundell. lVhen the calling and called subscribers are through conversing and hang up their receivers, supervisory relays 109 and 250 become denergized, and the latter opens the circuit of supervisory relay 119. Lamps 108 and 118 light up, whereupon the A-operator by removing plug 116 from jack 117 causes the deenergization of relay 202 which closes a circuit from ground through its armature and back contact, a contact 251 and the power magnet of sequence switch 206 to grounded battery for driving this sequence switch out of position 16 into position 18. A circuit is then closed from ground through a sequence switch contact 253 for actuating a magnet 255. Magnet 255 presses brush rod 238 against a roller 256, constantly rotating in the direction indicated by the arrow, for causing the restoration of selector 243. When the brush rod reaches its normal position, a circuit is closed from ground through commutator brush 242, a conducting segment 257, a contact 258 and the power magnet of sequence switch 206 to grounded battery, and the sequence switch is moved out of position 18 into position 1. The release of selector 248 and connector 219 may be accomplished in any well-known manner.

l/Vhat is claimed is:

1. In combination, a selectively operable switch, a plurality of controlling devices therefor, a plurality of finders, any one of which may associate one of said control ing 13o devices with said switch, an allotting arrangement for successively setting said finders in readiness for service, and means for preventing the starting of a finder after one of said finders has been set into operation.

2. In combination, a selectively operabl switch, a plurality of senders for controlling the operation of said switch, controlling mechanism associated with said switch, a plurality of finder switches each adapted to associate one of said senders with said switch, an allotting mechanism operable upon the completed operation of one of said finders for setting another finder in readiness for service, means operative in a certain position of said controlling mechanism for closing a starting circuit for all of said finders, and means for preventing the closure of said starting circuit in said position of the controlling mechanism after one of said switches has been started.

3.- In combination, a selector switch, a plurality of senders for controlling the operation of the same, a plurality of finder switches, a motor associated with each of the said finders to cause it to interconnect one of said senders and said selector switch, an allotter for setting one at a time said motors in readiness for operation, a sequence switch having a plurality of operating positions associated with said selector, a starting circuit for all motors closed in a certain position of said sequence switch, means operative upon the successful operation of one of said finders for actuating said allotter, and means for opening said starting circuit until said sequence switch has moved out of said certain position.

4. In combination, a selector switch, a plurality of senders, a plurality of finder switches, each adapted to connect one of said senders to said selector switch, a motor for each of said finder switches, a sequence switch having a plurality of operating positions associated with said selector switch, a starting circuit for all said motors closed in a certain position of said sequence switch, a relay for controlling said starting circuit, an allotter for rendering a single motor responsive to said starting circuit, means operative upon the successful operation of one of said finders for actuating said allotter to render another motor responsive to said starting circuit, and means for actuating said relay to open said starting circuit during the time elapsing between the operation of said allotter and the movement of said sequence switch out of said certain position.

5. In a telephone exchange system, a plurality of lines, a plurality of trunk lines, means including an automatic selector switch for establishing a connection between a calling and a called line, through one of said trunk lines, a plurality of senders for controlling the operation of said selector switch, a plurality of finder switches, each adapted to associate one of said senders with said last mentioned trunk line, a controlling apparatus associated with said selector switch, means operative upon the setting of one of said finder switches for allotting another finder switch for service, if said controlling apparatus is in a certain position, and means for preventing the starting of said last mentioned finder switch.

6. In a telephone exchange system, a plurality of lines, a plurality of trunk lines, means including an automatic selector switch for establishing a connection between a called and a calling line through a trunk line, a plurality of variably operable senders for controlling the operation of said selector switch, a plurality of finder switches, each adapted to associate one of said senders with said last mentioned trunk line, an allotter for setting the finder switches one at a time in readiness for service, means for operating the allotter finder switch while said selector switch is in a normal position, means operative in response to the starting of said sender for actuating said allotter, and means for preventing the operation of an allotted finder switch during the time elapsing between the allotment of said last mentioned finder switch and the starting of said selector switch.

7. In combination, a line, a plurality of finder switches, means associated with each of said switches to hunt for said line, allotting mechanism for successively setting into readiness for service said finder switches, means operated upon the completed setting of one of said finder switches for actuating said mechanism, and means for preventing the next allotted finder from hunting for said line.

In witness whereof, I hereunto subscribe my name this 19th day of September A. D., 1916.

ALBEN 13. LUNDELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

